nytimes.com – Continue reading the main story Share This Page Share Tweet Email Save more Continue reading the main story The idea seemed compelling: A blood pressure drug was found to block the effects of a gene mutation that causes Marfan syndrome, a condition that leads to terrible heart problems. The drug worked in mice with a gene that causes Marfan, doing just what everyone hoped it would do. A pilot study with 17 children showed the drug seemed to work in them, too, although there was no group that, for comparison, did not get the drug.